Many systems currently exist for mounting photovoltaic arrays onto trapezoidal metal roofs (a roof type that is especially common in Europe). Unfortunately, these existing systems often are complex, involve many parts, are expensive, and take an undesirably long time to install. Moreover, the installation of these systems typically requires specialized tools, or a number of different tools. What is instead desired is a mounting system that can be installed very rapidly on a metal roof and is also easily handled by an installer.
Trapezoidal roof mounting systems are not secured into building rafters. Instead, they are usually secured to the metal roofing material itself above the rafter. This is because the rafters typically run perpendicular to the peaks of the metal roofing material. As a result, these systems must be firmly attached directly to the metal roofing surface. In most existing systems, screws are driven directly through the metal roofing material. This can present several problems. First, working with small screws requires installers to fumble with small, loose parts while on the roof, as he or she tries to position and fasten them. Second, due to heat, any rooftop solar system, and in particular one located on a thermally conductive metal roof needs to have sufficient flexibility to account for thermal expansion and contraction through thousands of thermal cycles over the lifetime of a system. This problem is not addressed by mounting systems that are simply screw-fastened onto metal roofs. Third, due to the large number of parts used, existing trapezoidal roof mounting systems typically require excessive time to install. Fourth, existing trapezoidal roof mounting systems typically do not provide for module-to-module grounding; separate grounding wires typically need to be attached to these mounting systems.